Optoelectronic Processing Research Articles

Lateral Phase Heterojunction for Perovskite Microoptoelectronics.

Perovskite heterojunction engineering is the prerequisite but still a deficiency in the fabrication of micro-optoelectronic devices, where the present top-down or bottom-up techniques mainly focus on preparing the vertical heterojunction stacks. Perovskite lateral heterojunction structures generally rely on epitaxial growth, which cannot meet the demands of mass production of micro-devices. Here, a contact diffusion lithography technique is proposed to demonstrate a perovskite lateral phase heterojunction (LPH) polycrystalline film by ion-driven local phase transition. Under the guidance of thermodynamic simulations, methylamine contact and migration collectively promote in situ formation of α-phase formamidine-based perovskite patterns surrounded by δ-phase polymorphs. Spontaneous type-I heterojunction alignment between α- and δ-phases establishes energy funnels in the LPH film to facilitate carrier utilization and radiative recombination. The wide-bandgap δ-phase also serves as the coplanar isolator to achieve local anti-leakage for device integration. Based on the bright and stable LPH pattern layer, the near-infrared microscale perovskite light-emitting diode (micro-PeLED) with impressive device performance is achieved by following conventional device fabrication protocol. The proposed LPH enriches the perovskite heterojunction family, creates a new optoelectronic processing platform, and advances its versatile applications in micro-optoelectronics and photonics.

High-resolution SAR optoelectronic processor based on sensor-less adaptive optics

Studying phase error is central to synthetic aperture radar (SAR) research. Phase error due to the real motion status of the SAR platform and propagation effects can reduce the utility of high-resolution SAR images even with theoretical estimation-based phase error correction. Adaptive optics (AO) can be used to correct optical aberrations. This study proposes an advanced, high-resolution SAR optoelectronic processor by integrating conventional processors with sensor-less AO techniques. This processor provides accurate adaptive phase error correction capabilities. The processing results of SAR echo data demonstrate the effectiveness of the proposed system in adaptive phase error correction and imaging improvement.

Metal-organic framework single crystal for in-memory neuromorphic computing with a light control

Neuromorphic architectures, expanding the limits of computing from conventional data processing and storage to advanced cognition, learning, and in-memory computing, impose restrictions on materials that should operate fast, energy efficiently, and highly endurant. Here we report on in-memory computing architecture based on metal-organic framework (MOF) single crystal with a light control. We demonstrate that the MOF with inherent memristive behavior (for data storage) changes nonlinearly its electric response when irradiated by light. This leads to three and more electronic states (spikes) with 81 ms duration and 1 s refractory time, allowing to implement 40 bits s−1 optoelectronic data processing. Next, the architecture is switched to the neuromorphic state upon the action of a set of laser pulses, providing the text recognition over 50 times with app. 100% accuracy. Thereby, simultaneous data storage, processing, and neuromorphic computing on MOF, driven by light, pave the way for multifunctional in-memory computing architectures.

Synergetic Responses of Multiple Functions Induced by Phase Transition in Molecular Materials.

Materials that integrate magnetism, electricity and luminescence can not only improve the operational efficiency of devices, but also potentially generate new functions through their coupling. Therefore, multifunctional synergistic effects have broad application prospects in fields such as optoelectronic devices, information storage and processing, and quantum computing. However, in the research field of molecular materials, there are few reports on the synergistic multifunctional properties. The main reason is that there is insufficient awareness of how to obtain such material. In this brief review, we summarized the molecular materials with this characteristic. The structural phase transition of substances will cause changes in their physical properties, as the electronic configurations of the active unit in different structural phases are different. Therefore, we will classify and describe the multifunctional synergistic complexes based on the structural factors that cause the first-order phase transition of the complexes. This enables us to quickly screen complexes with synergistic responses to these properties through structural phase transitions, providing ideas for studying the synergistic response of physical properties in molecular materials.

DUV optoelectronic bionic synapse based on the MOCVD-deposited amorphous gallium oxide film

Optoelectronic bionic synapses, integrating sensing and processing capabilities, help to break through the limitations of von Neumann structure and are promising in smart sensors, AI robots etc. fields. Here, we fabricated a deep ultraviolet (DUV) optoelectronic bionic synapse with an amorphous gallium oxide (a-GaOx) film deposited by metal–organic chemical vapor deposition (MOCVD). DUV illumination pulses could be facilely written into the bionic synapse, and the written information exhibits non-volatility. By manipulating the illumination pulse number, the pulse width, and the pulse power density, the synapse is capable of transitioning from short-term memory (STM) to long-term memory (LTM), effectively emulating the learning-memory behavior of human brains.

Non-volatile rippled-assisted optoelectronic array for all-day motion detection and recognition

In-sensor processing has the potential to reduce the energy consumption and hardware complexity of motion detection and recognition. However, the state-of-the-art all-in-one array integration technologies with simultaneous broadband spectrum image capture (sensory), image memory (storage) and image processing (computation) functions are still insufficient. Here, macroscale (2 × 2 mm2) integration of a rippled-assisted optoelectronic array (18 × 18 pixels) for all-day motion detection and recognition. The rippled-assisted optoelectronic array exhibits remarkable uniformity in the memory window, optically stimulated non-volatile positive and negative photoconductance. Importantly, the array achieves an extensive optical storage dynamic range exceeding 106, and exceptionally high room-temperature mobility up to 406.7 cm2 V−1 s−1, four times higher than the International Roadmap for Device and Systems 2028 target. Additionally, the spectral range of each rippled-assisted optoelectronic processor covers visible to near-infrared (405 nm–940 nm), achieving function of motion detection and recognition.

Measurement of phase modulation time dynamics of liquid crystal spatial light modulator

Liquid crystal spatial light modulators for precise dynamic manipulation of coherent light fields, used in diffractive optoelectronic optical data processing systems, are considered. This paper presents the results of a study of the temporal dynamics of the HoloEye PLUTO-2 VIS-016 liquid crystal spatial light modulator for analysis of light fields rate modulation. Experiments using binary phase computer generated holograms and binary focusing phase diffractive optical elements were conducted. Based on experimental data, the time characteristics of the modulator response were determined. It was found that when the rise time of the diffraction efficiency was 146 ms after the hologram displaying onto the SLM, and when switching to a new hologram, the decay time was 97 ms. These results allowed the dynamic generation of an alternating holograms at a refresh rate of 2 Hz with an interference level of –16 dB. Increasing the frequency of fringe pattern updates increases the level of interframe noise in the generated holograms, and when updated at the specification frequency, the generated distributions cannot be separated. Determining the actual frame rate based on the rise and decay times of the diffraction efficiency makes it possible to correctly calculate the minimum operating time of an information optical system containing a liquid crystal spatial light modulator.

Size control of MoS2 quantum dots by varying the crystallographic orientation of sapphire substrates

The phenomena in size-dependent optoelectronic and catalytic properties of MoS2 quantum dots make them attractive in fabricating optoelectronic devices and processing water-splitting. However, growing monolayered MoS2 quantum dots with controlled sizes is challenging and has never been realized on a solid-state substrate. Herein, we experimentally demonstrate the size of monolayered MoS2 quantum dots can be thermodynamically manipulated by varying the orientation of the sapphire substrate from c plane, m plane to r plane and the size can be tuned from 10 nm to 2 nm. An apparent shift in the optical absorption and outstanding size-dependent electrocatalytic capability of the MoS2 quantum dots can be featured. The DFT results verify that the size modulation is associated with the interaction strength between the MoS2 quantum dots and the sapphire substrate. This work provides a new benchmark in the growth of size-tunable monolayered MoS2 quantum dots on a solid-state substrate.

Micro-holographic effects with sub-7nm photonic CMOS transistors for nonlinear optoelectronic processors and optical computers

Micro-holographic effects with sub-7nm photonic CMOS transistors for nonlinear optoelectronic processors and optical computers

Chiro-Optoelectronic Encodable Multilevel Thin Film Electronic Elements with Active Bio-Organic Electrolyte Layer.

It is suggested that chiral photonic bio-enabled integrated thin-film electronic elements can pave the base for next-generation optoelectronic processing, including quantum coding for encryption as well as integrated multi-level logic circuits. Despite recent advances, thin-film electronics for encryption applications with large-scale reconfigurable and multi-valued logic systems are not reported to date. Herein, highly secure optoelectronic encryption logic elements are demonstrated by facilitating the humidity-sensitive helicoidal organization of chiral nematic phases of cellulose nanocrystals (CNCs) as an active electrolyte layer combined with printed organic semiconducting channels. The ionic-strength controlled tunable photonic band gap facilitates distinguishable and quantized 13-bit electric signals triggered by repetitive changes of humidity, voltage, and the polarization state of the incident light. As a proof-of-concept, the integrated circuits responding to circularly polarized light and humidity are demonstrated as unique physically unclonable functional devices with high-level logic rarely achieved. The convergence between functional nanomaterials and the multi-valued logic thin-film electronic elements can provide optoelectronic counterfeiting, imaging, and information processing with multilevel logic nodes.

Brain-like optoelectronic artificial synapses with ultralow energy consumption based on MXene floating-gates for emotion recognition

In the new generation of brain-like optoelectronic visual signal processing and artificial perception systems, floating-gate artificial synaptic devices based on two-dimensional materials represent a feasible route.

Single-shot measurement of wavelength-resolved state of polarization dynamics in ultrafast lasers using dispersed division-of-amplitude

Characterization of the state of polarization (SOP) of ultrafast laser emission is relevant in several application fields such as field manipulation, pulse shaping, testing of sample characteristics, and biomedical imaging. Nevertheless, since high-speed detection and wavelength-resolved measurements cannot be simultaneously achieved by commercial polarization analyzers, single-shot measurements of the wavelength-resolved SOP of ultrafast laser pulses have rarely been reported. Here, we propose a method for single-shot, wavelength-resolved SOP measurements that exploits the method of division-of-amplitude under far-field transformation. A large accumulated chromatic dispersion is utilized to time-stretch the laser pulses via dispersive Fourier transform, so that spectral information is mapped into a temporal waveform. By calibrating our test matrix with different wavelengths, wavelength-resolved SOP measurements are achieved, based on the division-of-amplitude approach, combined with high-speed opto-electronic processing. As a proof-of-concept demonstration, we reveal the complex wavelength-dependent SOP dynamics in the build-up of dissipative solitons. The experimental results show that the dissipative soliton exhibits far more complex wavelength-related polarization dynamics, which are not shown in single-shot spectrum measurement. Our method paves the way for single-shot measurement and intelligent control of ultrafast lasers with wavelength-resolved SOP structures, which could promote further investigations of polarization-related optical signal processing techniques, such as pulse shaping and hyperspectral polarization imaging.

Diffraction characteristics of orthogonal gratings analysis based on a spatial light modulator.

The diffraction characteristics of orthogonal gratings with variable duty cycles and phase modulation depths are analyzed by using a spatial light modulator. The calculation methods of the transmission function, far-field diffraction light field, and diffraction efficiency of orthogonal gratings are deduced in theory. Meanwhile, the influences of the duty cycle and phase modulation depth on the diffraction characteristics of the orthogonal grating are discussed. The simulation and experimental results verify the correctness of the theoretical derivation. This method can be widely used in the fields of an optical vortex array, laser parallel processing, optical computing, optical communication, and optoelectronic hybrid processing.

Low-threshold single-mode laser in perovskite microdiscs direct-synthesized into planar microcavity

Low-threshold single-mode laser in CsPbBr3 microdiscs grown between two distributed Bragg reflectors (DBRs) is realized at room temperature. The CsPbBr3 microdiscs are directly synthesized on the surface of prepared first-half DBRs microcavity by a chemical vapor deposition method. This scheme avoids possible surface damage or contamination caused by the traditional transfer of sample into the DBRs. The single-mode laser with low threshold (∼1.3 μJ/cm2) was obtained in the CsPbBr3 microdiscs sandwiched in DBRs and measured by using the micro-photoluminescence spectroscopy. The length of the resonant cavity is short enough to support a large free spectral range, which ensures only one mode in the bandwidth of the optical gain. Moreover, by modulating the thickness of the CsPbBr3 microdiscs, the wavelength of single-mode laser emission can be broadly tuned from 529.6 to 544.1 nm. This work provides a method of fabricating single-mode laser in DBRs, which may have potential applications in on-chip integration of optoelectronic devices and signal processing.

Field-effect silicon-plasmonic photodetector for coherent T-wave reception

Plasmonic internal photoemission detectors (PIPED) have recently been shown to combine compact footprint and high bandwidth with monolithic co-integration into silicon photonic circuits, thereby opening an attractive route towards optoelectronic generation and detection of waveforms in the sub-THz and THz frequency range, so-called T-waves. In this paper, we further expand the PIPED concept by introducing a metal-oxide-semiconductor (MOS) interface with an additional gate electrode that allows to control the carrier dynamics in the device and the degree of internal photoemission at the metal-semiconductor interfaces. We experimentally study the behavior of dedicated field-effect (FE-)PIPED test structures and develop a physical understanding of the underlying principles. We find that the THz down-conversion efficiency of FE-PIPED can be significantly increased when applying a gate potential. Building upon the improved understanding of the device physics, we further perform simulations and show that the gate field increases the carrier density in the conductive channel below the gate oxide to the extent that the device dynamics are determined by ultra-fast dielectric relaxation rather than by the carrier transit time. In this regime, the bandwidth can be increased to more than 1 THz. We believe that our experiments open a new path towards understanding the principles of internal photoemission in plasmonic structures, leading to PIPED-based optoelectronic signal processing systems with unprecedented bandwidth and efficiency.

USING THE PRINCIPLES OF AUTOMATED OPTICAL IMAGE RECOGNITION TO ASSESS THE STRUCTURAL STABILITY OF KNITTED FABRICS

The article shows the possibility of determining the characteristics of stretch deformation of knitted fabrics by optoelectronic processing of digital images using the developed software. The technique is applicable for knitted fabrics of sparse structures of any fibrous composition. The tests are carried out on a developed device that implements the possibility of spatial deformation of the samples. As a quantitative indicator of the change in the structure of the knitted fabric under tension, a coefficient, that characterises the change in the structure by increasing the through porosity of the fabric, is used. The stability of the structure of the knitted fabric is evaluated by an indicator that determines the recoverability of the loop structure after rest. The method was tested on linen knitted fabrics. The results of experimental studies should be used at the design stage of products to create knitted fabrics resistant to the action of operational loads.

Microwave photonics approach as a novel smart fabrication technique of a radio communication jammers

Abstract A novel technique to fabricate a responsive radio communication jammer, the purpose of which is to suppress a radio signal with a detonation code as well as to interfere communication link due to Denial-of-Service effect is proposed and highlighted. The distinctive feature of our approach is to the process received radio signals, when instead of the operation of introducing noise interference into each radio channel exclusively used in existing multi-channel jammers, a common single-channel device with optoelectronic processor is exploited, which generates many replicas of received radio signal that critically degrade its signal-to-interference ratio so that the remote-controlled detonators of the explosive installed at the objects cannot be triggered. The results of our investigations to computer-aided design a response time performance of the proposed jammer using a co-simulation of specialized optoelectronic computer tool VPI Photonics Design Suite and a versatile Matlab software. The layout and results of proof-of-concept experiment that validate the simulation are presented and discussed.

Optical SAR data processing configuration with simultaneous azimuth and range matching filtering.

The real-time processing of synthetic aperture radar (SAR) data has a high requirement for the processor, which is a difficult problem in SAR real-time processing. With the rapid development of optoelectronic devices, traditional electrical SAR data processing can be converted into optoelectronic processing to improve the processing speed. In this paper, a new type of optical device is proposed to improve the processing speed of SAR data. With the help of a spatial light modulator (SLM), the initial SAR signal and matched filter function are loaded on the input plane and spectrum plane of the 4f system, respectively. Using an optical lens with the function of the Fourier transform, the Fourier transform and inverse Fourier transform of the SAR signal are carried out to realize the fast imaging of SAR. In theory, the processing speed of SAR data is the speed of light. Compared with traditional methods such as the range-Doppler (RD) algorithm, it is no longer necessary to carry out a one-dimensional Fourier transform but to carry out matching filtering for the azimuth and range of the spectrum plane of 4f system at the same time. In this way, it is not necessary to introduce a cylindrical lens, only a spherical lens is needed to realize the Fourier transform imaging of SAR. Finally, a two-dimensional SAR processing optical system is built to obtain the SAR image in real time.

Studying Microwave-Photonics Design Principle of a Responsive Jammer for Radio-Controlled Explosive Devices

A new approach to design an ultra-wideband device for blocking radio-controlled explosive apparatuses, in which a multi-channel processing unit based on a set of narrow-band radio signal receiving units with the introduction of noise interference into each channel has been replaced by a single-channel microwave photonic analogue using an optical recirculating circuit-based optoelectronic radio signal processor to suppress the transmission channel, is proposed and previously investigated. The block diagram and results of computer simulation of the optoelectronic processor are described for the transmission of standard radio telecommunication signals, confirming the possibility and determining the key conditions for blocking a radio channel.

Effect of the Coherence Time of the Semiconductor Laser Emitter on the Quality of Radio Signal Processing in the Optoelectronic Delay-Line Processor

The effect of the coherence time of the semiconductor laser emitter incorporated in the most commonly used optoelectronic radio signal processor (OERSP) based on a multitapped optical delay circuit (ODC) on the transmission gain and signal-to-noise ratio at the device output is studied by computer simulation in a widely used optoelectronic CAD tool. It is found that efficient operation of a practical device implies that its coherence time should be shorter than the duration of the processed radio-frequency signal at least by an order of magnitude. Measurements of coherence times of three most commonly used modern emitters: the external-cavity-based laser, distributed feedback laser, and Fabry—Perot laser show that only the latter type can be efficiently used as a part of the studied OERSP with a four-tapped ODC based on 7-core optical fiber.